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Okay, I have sifted through threads on the correct KTMP of our vehicles (I am referring to the read-out from instrument cluster test NR-07). I have seen folks complain that their car was not coming up to the suggested 79-degree Celsius threshold, which seems to indicate a failed thermostat in the open position (the way it is meant to fail thankfully).

A few months ago, I had to have my radiator and water pump replaced due to an exploding fan as a result of a failed fan clutch (I'm sure you can fill in the blanks as to the horrors of what happened due to my own idiocy of not realizing what was broken). Anyhow, since that time, I've noticed my oil temp when heated up would sit at about 205 on the analog dial and analog water temp would be at 11:30 position (i.e., just left of center). Since the repair, I've noticed the water temperature sits at dead center and the oil temp gets more around 212-220 (whatever slightly to the right of six o'clock would be). It's definitely been a hot summer for us, but I've been through six other summers with this car without noticing that kind of temperature, only slightly elevated though it may be.

So anyway, I started regularly checking my KTMP while driving over the past few weeks and, once the car is warmed up, it seems to hover -- even on the highway at cruising speeds -- between 90 and 94 degrees Celsius. While no posts I've seen here indicate that this is -dangerous-, it seems to be out of range compared to what most others experience -- especially if the thermostat is designed to have a threshold of 79 degrees C. I haven't really been getting the readout on the OTEMP, but I'm going to start checking that out too.

I am just wondering if something was tweaked by the mechanic who did the job and/or he got maybe a generic E39 part where an E39 M5 one was called for. So (1) should I even care or am I just overreacting, and (2) if I'm not, what could cause this? As always, I am very grateful for your reading, digesting, and subsequent analysis of this situation!

BTW, I am running BMW/Castrol/TWS.
 

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90-94 does seem on the high side. That's the sort of temperature I see when stuck in traffic on a hot (high 20's C) day, I saw 98 on the motorway last Tuesday, this drops to mid 80's almost as soon as you start moving at a reasonable speed.

However, to put this in perspective, the V8 N62 engine has a normal operating temperature of 110 C.
 

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Agree, seems a bit hot. Basics, , , Does the radiator pass muster on a simple visual inspection, no blockages etc (expect it should, but couldn't hurt to ask) and then is the fluid full, just making sure that it hasn't bleeded air and then fluid could need topping. Basics, but worth checking.

Assuming the thermostat was not done at the time of rad and fan clutch replacement then.?
 

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Are you comparing KTEMP pre and post radiator install in different ambient temp conditions? How about seasonally adjusted temp? It will always run a few degrees hotter in the summer months.
 
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To OP:

Your KTEMP is fine. Just because the Thermostat is designed to open at 79C it doesn't mean the coolant temp will be 79C. Our engines produce a lot of heat and the clutch fan with the aux fan are just not sufficient to maintain a 79C coolant temp. Also note that it has been very hot and humid this summer. My friends 03 M5 and mine both run at similar temps when it's above 90F outside, I been to NY several times over the past week and can vouch that its VERY HOT and NJ is not that far. I suggest you drive and enjoy.

The only way to find out if you do have an issue with coolant system is when it's much cooler outside and you still reach those numbers on Ktemp.
 

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Relax....:tonquesmilie:
 

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Kumaran, where was the coolant temp needle at this temp, still at 12 0'clock?
No, actually just to the right of 12 o' clock, no where near the red zone though....

This totally RARE needle deflection to right of norm, made me immediately get KTMP up on the cluster, and also turn the HVAC heating on a bit....I sort of managed to maintain it below 110 Deg C....I was really giving the car very lengthy WOT bursts, in 30 Deg C Ambient temps, on some pretty serious ascents in Italy somewhere, keeping pace with my mates Ferrari California, driven as if it was worth £1500 rather than £150,000....


As soon as the ascending ceased, it all came back to normal, even though the pace did not abate !
 

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Your oil looks like its at about 120 in that pic. I'm guessing your blower helps keep that high
Only really in the scenario I described previously.

I drive hard, but only saw those temps, during the heavy ascent chase.
 

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OT: Kumaran, your car has a US cluster? Maybe I didn't pay attention a back story?

Sent from my Samsung Galaxy S™ II, Epic™ 4G Touch (Sprint) using Tapatalk 2
 

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OT: Kumaran, your car has a US cluster? Maybe I didn't pay attention a back story?

Sent from my Samsung Galaxy S™ II, Epic™ 4G Touch (Sprint) using Tapatalk 2
Interesting, why do you suggest that ?

Its got Oil in Deg C and it says MPH UK....
:dunno:
 

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I didn't see the UK. Looks like I need to find a black UK cluster then.

More to the point, I had no idea a MPH/Celsius cluster existed. It is a combination I have wanted for years and thought was only possible through customization.

Or, are all UK clusters like this? I just assumed they were scaled major in kilometers, I guess.

Sent from my Samsung Galaxy S™ II, Epic™ 4G Touch (Sprint) using Tapatalk 2
 

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UK ones are scaled major in MPH like US ones.

I'll get hold of a black one for you and send it over if you'd like ??
 

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UK ones are scaled major in MPH like US ones.

I'll get hold of a black one for you and send it over if you'd like ??
I would very much appreciate that!!!!

Still learning about the car even today!

Sent from my Samsung Galaxy S™ II, Epic™ 4G Touch (Sprint) using Tapatalk 2
 
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I would very much appreciate that!!!!

Still learning about the car even today!

Sent from my Samsung Galaxy S™ II, Epic™ 4G Touch (Sprint) using Tapatalk 2
OK ! I am on it ! :flag:
 

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